JP4756213B2 - A water-impervious test method at the in-situ location of the borehole plugging material, a water-imperviousness test system at the location of the borehole plugging material, a method of analyzing the hydraulic conductivity of the top of the borehole plugging material, a strength analysis method of the top of the borehole plugging material, and boring Experimental equipment for water blocking chamber for hole blocking material - Google Patents

Description

The present invention covers all technologies involving geological disposal of high-level radioactive waste, geological disposal of low-level radioactive waste, groundwater, oil, natural gas, geothermal, hot springs, metals, civil engineering, scientific research and other drilling holes. The present invention relates to a measurement method, a measurement system, an analysis method, and an indoor experiment apparatus used in the field.
More specifically, the present invention relates to a measurement method for testing the water-blocking performance, permeability coefficient and strength of a plugging material placed in a borehole, a measurement system used therefor, an analysis method used for the measurement, and these The present invention relates to an indoor test apparatus that performs a simulation in a room.
Specifically, the present invention performs a water shielding test method at a blocking material in-situ position of a boring hole and a water shielding test at a blocking material in-situ position of a boring hole. Water blocking test system at the in situ position of the borehole plugging material that can be drilled, a method for analyzing the permeability coefficient of the top of the borehole plugging material, a strength analysis method for the top of the borehole plugging material, and a test facility for the borehole plugging material Is.

Conventionally, various materials such as bentonite, cement, sand, aggregates, packers, etc. have been used as plugging materials in order to plug the boreholes in the above technical fields. Almost no consideration is given, and the current situation is that it is regarded as water shielding performance with the physical property values obtained by laboratory tests and field tests, etc., for each plugging material.
However, for example, in the field of geological disposal of high-level radioactive waste, if the water blocking by the plugging material is insufficient, the borehole itself may become a passage connecting the geological environment to be isolated and the ground. Yes, it greatly affects the safety of natural barriers that are the prerequisite for geological disposal. For such boring holes, long-term, safe and reliable plugging work is required, and in such plugging work, a blocking material mainly composed of bentonite is suitable for long-term stability. ing.
Although it is necessary to strictly evaluate the water shielding performance even after the plugging material is placed, the current technology measures and evaluates the water blocking property of the plugging material placed in the borehole in the original position of the plugging material. There is no way.

For example, as a result of a literature survey conducted in 2003 “Development of borehole clogging technology” and overseas interviews, underground research facilities in the United States, Switzerland, Sweden, etc., which have advanced research institutions for high-level radioactive waste geological disposal research The development of similar methods has not yet been realized, and the current situation is that there is no choice but to estimate the actual occlusion state based on the performance values obtained in laboratory tests or field tests.
A test method is provided in which a probe having a Packard is inserted into a test boring hole, the test section of the test boring hole is divided by a probe packer, and the pressure in the test section is detected by a sensor to test the water permeability. (Patent Document 1).
JP-A-6-146251

As in the prior art in the first half described above, the actual situation is that there is no choice but to estimate the actual occlusion state based on the performance values obtained in laboratory tests or field tests.
In addition, as in the prior art described in the above cited document 1, although in-situ permeability tests can be performed in ordinary geological formations, permanent clogging is required, so that a borehole for high-level radioactive waste geological disposal is required. The current situation is that a water permeability test on the blockage is not possible.
This test equipment is used for geological disposal of high-level radioactive waste, geological disposal of low-level radioactive waste, groundwater, oil, natural gas, geothermal, hot springs, metal, civil engineering, scientific surveys, and all other drilling holes. In the technical field, the obstruction material placed in the borehole during the borehole closure work is carried out for the purpose of hindering the advection of underground fluid such as groundwater from the formation at a certain depth to the formation located above and below it. It is an object of the present invention to provide a novel technique capable of demonstrating the blocking effect and safety by measuring the water shielding performance in situ.

In order to achieve the above object, according to the first aspect of the present invention, there is provided a water shielding test method at a boring hole blocking member in-situ position, wherein the measuring probe is lowered to the top of the blocking material blocking the boring hole and the boring hole is formed by the measuring probe. A step of shielding the upper and lower sides of the measuring probe, and after the boring hole is shielded from the upper and lower sides of the measuring probe in the step, water is poured into the top of the blocking material on the lower side of the measuring probe with a predetermined measurement pattern, and a predetermined measurement is performed. A step of measuring pressure and temperature according to a pattern to determine a water permeability coefficient, a step of further injecting water again to acquire a break pressure to determine the strength of the plugging material, and a step of determining the strength of the plugging material. And the step of releasing the shielding after the completion of the step and taking out the measurement probe from the boring hole.
In order to achieve the above object, a water blocking test system in the in situ position of a closing material for a borehole according to the invention described in claim 2 includes an inflatable packer of a type that is expanded by gas pressure or water pressure and is in close contact with the wall surface of the borehole. A measurement base container provided at the lower end of the inflatable packer, a water injection outlet provided in the measurement base container, capable of supplying water at a minute flow rate, and also serving as an inlet for pressure measurement, and One or two or more pressure measurement inlets provided at a predetermined distance in the horizontal direction from the water injection outlet provided in the measurement base container, and pressures respectively attached to the pressure measurement inlets A temperature measurement sensor, a water injection container provided in a portion that becomes an upper part of the expansion packer when the expansion packer is installed in the boring hole, and a water injection container stored in the water injection container. A water injection means for injecting water into the water injection outlet so that the water injection can be controlled at a constant or constant pressure with a pressure that does not deform the blocking material, and a measurement probe formed into a shape that can be inserted into the borehole; After the measurement base of the measurement probe is placed on the top of the blocking material of the borehole, a gas pressure or a water pressure of a predetermined pressure is supplied to the inflatable packer at the time of measurement to firmly fix the bottom surface of the measurement base container to the blocking material A packer control device that reduces the gas pressure or water pressure at the end of measurement and water injection of the water injection means of the measurement probe at a constant flow rate or constant pressure at a pressure that does not deform the blocking material. After the water is poured for a certain period of time, the water injection is stopped and a water injection stop section is provided. A measurement / control device that takes in measurement data from the pressure / temperature measurement sensor according to a measurement pattern and calculates the hydraulic conductivity of the blocking material original position or the strength of the blocking material original position from the acquired measurement data It is characterized by comprising.
According to a third aspect of the present invention, there is provided a water-imperviousness test system in a boring hole blocking member in-situ position, wherein the water injection means includes a micro flow metering pump, a discharge port of the micro flow metering pump, and a capillary tube. It is equipped with a solenoid valve that prevents backflow when the bore pressure is higher than the pump pressure, and a storage container that supplies water to the suction port of the micro flow metering pump. In addition, water can be supplied to a water injection outlet provided in the measurement base container via a capillary tube.
According to a fourth aspect of the present invention, there is provided the water-blocking test system at the original position of the closing material of the borehole, wherein the micro flow rate metering pump drives a piston in a cylinder with an electric cam and a shaft. It is characterized by comprising a plunger-type pump that makes it possible to feed a certain amount of water.
In order to achieve the above object, the method of analyzing the permeability coefficient of the top of the borehole closing material according to the invention as claimed in claim 5 is to insert the tip of the measurement probe into the top of the closure material closing the borehole, and to open the borehole by the measurement probe. Pressure measurement data in a step of shielding the upper and lower sides of the measurement probe, a step of pouring water at a constant flow rate or a constant pressure at a pressure that does not deform the blocking material for a certain period of time, and a water pouring stop section after the water pouring is stopped. And a step of analyzing the pressure measurement data obtained in the step to obtain a hydraulic conductivity coefficient of the water injection stop section.
In order to achieve the above object, the strength analysis method of the top of the borehole closing material according to the invention of claim 6 is directed to lowering the measurement probe to the top of the closure material closing the borehole and measuring the borehole with the measurement probe. A step of shielding the upper and lower sides of the probe, and after blocking the upper and lower sides of the measuring probe in the step, water is poured into the top of the blocking material on the lower side of the measuring probe with a predetermined measurement pattern, and pressure is applied by the predetermined measurement pattern. The step of acquiring the temperature, the step of further injecting water again to acquire the break pressure after the completion of the step, the strength of the plugging material determined by the physical property test of the plugging material subjected to the indoor water permeability test, and the step A step of determining the strength of the plugging material placed in the borehole based on the relationship with the acquired break pressure. That.

According to the present invention, in setting safety standards for closing work at the time of closing a survey borehole to be carried out when selecting a disposal site for high-level radioactive waste geological disposal or low-level radioactive waste geological disposal. An evaluation method can be established. As a result, at the disposal site, the degree of freedom in selecting the survey boring point can be increased by eliminating the anxiety about the uncertainty of the blockage operation after the completion of the survey due to the implementation of the survey boring. It also has the effect of increasing the survey boring points and improving the accuracy of the survey, and reducing the uncertainty in selecting a disposal site.
In addition to the radioactive waste geological disposal field, how to prevent the migration of pollution sources to groundwater is a major issue in the groundwater pollution field. In particular, it is a serious problem for the source of contamination to be connected to an uncontaminated groundwater formation through a well. By using this test method and equipment, it is possible to improve the reliability of groundwater contamination countermeasures implemented by the national and local governments by providing one inspection standard for these blockage operations.

The best mode for carrying out the present invention will be described below with reference to the drawings.
<Explanation of water-imperviousness test system at the original position of the blocking material in the borehole>
FIGS. 1 to 5 are views for explaining a water-imperviousness test system in a blocking material original position of a boring hole according to an embodiment of the present invention.
FIG. 1 is a configuration diagram showing a water-imperviousness test system at a blocking material original position of a boring hole according to an embodiment of the present invention. FIG. 2 is a cross-sectional view showing a detailed configuration of the measurement probe used in the water-imperviousness test system in the blocking member original position of the boring hole according to the embodiment. FIG. 3 is a view showing the bottom surface of the measurement base container of the measurement probe used in the water-imperviousness test system in the blocking material original position of the boring hole according to the embodiment.

  In FIG. 1, a water-imperviousness test system 1 at a blocking material original position of a boring hole according to an embodiment of the present invention is roughly divided into a measuring probe 3 formed into a cylindrical shape that can be inserted into a boring hole 2. The packer drive control device 5 capable of expanding and contracting the inflatable packer 30 which is a partial component of the measurement probe 3, the measurement pressurization control based on the measurement pattern on the measurement probe 3, and the measurement pattern Measurement / control device 7 that can determine the hydraulic conductivity or the strength of the plugging material in-situ from the information obtained by measurement, and other measurement probes 3 inserted into or removed from the borehole 2 The auxiliary mechanism 9 is configured.

As shown in FIGS. 1 and 2, the measurement probe 3 includes an inflatable packer 30, a measurement base container 31 provided in the lower part of the inflatable packer 30, and water injection provided in the upper part of the inflatable packer 30 in the figure. And a cable head 34 covering the upper end portion of the moat tube 33 shown in the figure and formed concentrically in a cylindrical shape. Yes.
The measurement probe 3 is inserted into or removed from the borehole 2 when the measurement auxiliary mechanism 9 moves down or raises the logging cable 11 extended from the cable head 34. It has become.

More specifically, the measurement probe 3 has the following configuration. In other words, the inflatable packer 30 communicates with the packer drive control device 5 via the high-pressure tube 13 for holes, and the gas pressure or the pressure supplied from the packer drive control device 5 via the high-pressure tube 13 for holes or It is a packer of a system that expands by water pressure and adheres closely to the wall surface of the boring hole 2.
As shown in FIG. 3, the bottom surface 31 a of the measurement base container 31 is capable of supplying water at a minute flow rate, and the water injection outlet 35 serving also as the pressure measurement inlet 35 a and the measurement base container 31. One or two or more pressure measurement inlets 36 are provided at predetermined positions that are provided on the bottom surface 31a and are separated from the water injection outlet 35 serving also as the pressure measurement inlet 35a in the horizontal direction.

Measurement sensors 37 and 38 are accommodated inside the measurement base container 31. The pressure / temperature measurement sensor 37 communicates with and is attached to the pressure measurement inlet 35a. The pressure measurement sensor 38 communicates with and is attached to the pressure measurement introduction port 36.
A water injection means 39 is accommodated in the water injection section container 32. The water injection means 39 can inject water into the water injection outlet 35 via a capillary tube 390 so that the water injection can be controlled at a constant or constant pressure.
The water injection means 39 of the measurement probe 3 includes a minute flow rate metering pump 391 and an electromagnetic valve 392 provided between the discharge port of the minute flow rate metering pump 391 and the capillary tube 390 to prevent backflow when the pressure in the hole is higher than the pump pressure. And a water storage container 393 for supplying water to the suction port of the minute flow rate metering pump 391. Water is supplied to the water injection outlet 35 through the discharge port of the minute flow rate metering pump 391, the electromagnetic valve 392, and the capillary tube 390. It can be done.

More specifically, the pressure / temperature measurement sensor 37 provided in the measurement base container 31 of the measurement probe 3 is connected to the cable connector 15 via the first signal cable 371. A pressure measurement sensor 38 provided in the measurement base container 31 of the measurement probe 3 is connected to the cable connector 15 via a second signal cable 381.
A micro flow metering pump 391 is connected to the cable connector 15 via a first power cable 391a, and the power for driving the micro flow metering pump 391 is very small via the first power cable 391a. The flow rate metering pump 391 can be supplied. Similarly, an electromagnetic valve 392 is connected to the cable connector 15 via a second power cable 392a, and electric power for on / off driving control of the electromagnetic valve 392 is provided via the second power cable 392a. The electromagnetic valve 392 can be supplied.

The cable connector 15 is connected to a measurement / control device 7 installed on the ground via a collective cable 17, a connector 19, and a logging cable 11. The logging cable 11 is composed of a multicore cable for use in the hole, and the number of the first signal cable 371, the second signal cable 381, the first power cable 391a, and the second power cable 392a. The number of lines is sufficient to satisfy the above.
The measurement auxiliary mechanism 9 includes a winch 91 having a drum for winding the logging cable 11, a pulley 92 fixed on the ground, and a pulley 93 for inserting and removing the measurement probe 3 from the boring hole 2. The logging cable 11 for suspending the measurement probe 3 is wound around the drum of the winch 91 via the pulley 93 and the pulley 92, and vice versa.

Here, the minute flow rate metering pump 391 of the water injection means 39 will be described. FIG. 4 is a diagram showing a basic configuration of a micro flow rate metering pump constituting water injection means provided in a measurement probe used in a water-imperviousness test system in a blocking material original position of a boring hole according to the embodiment of the present invention. It is.
In FIG. 4, the minute flow rate metering pump 391 is a plunger type pump that feeds water at a constant flow rate by driving a piston 3914 inside a cylinder 3913 with an electric cam 3911 and a shaft 3912. A water supply port 3915 and a water injection port 3916 of the minute flow rate metering pump 391 are connected to an electromagnetically operated valve 392, and water is supplied through a water supply pipe 3921 connected to the water storage container 393, and water is injected through a capillary tube 390 connected to the water injection outlet 35. I do. There are two electromagnetically operated valves, and the check valve prevents the back flow by operating only in the direction of entering the cylinder 3913 at the water supply pipe 3921-water supply port 3915 and in the direction of exiting from the cylinder 3913 at the water injection port 3916-pipe 3922. Yes. In this way, the minute flow rate metering pump 391 is configured by a plunger type pump that can feed a fixed amount of water by driving the piston 3914 inside the cylinder 3913 by the electric cam 3911 and the shaft 3912. .

FIG. 5 is a diagram showing a water-imperviousness test system in a blocking material original position of a boring hole according to an embodiment of the present invention.
FIG. 5 is a diagram showing a water-imperviousness test system in the original position of the blocking material in the borehole according to the embodiment of the present invention, and the same components as those shown in FIGS. 1 to 4 are the same. A description will be given with reference numerals.

In FIG. 5, the measurement / control device 7 includes a pressure / temperature measurement sensor 37 and a pressure measurement sensor 38 via a data logger 8 inside the measurement probe 3 through a logging cable 11 made of a multicore cable for hole. It is connected to the. Similarly, the measurement / control device 7 is connected to a micro flow rate metering pump 391 via a pump control electronic device 10 inside the measurement probe 3 through a logging cable 11 made of a multicore cable for hole, It is also connected to a solenoid valve 392 (not shown).
The packer drive control device 5 includes a packer control device 51 and a high-pressure pump 52 that is operation-controlled by the packer control device 51. The discharge port of the high-pressure pump 52 is connected to the inflatable packer 30 of the measurement probe 3 through the high-pressure tube 13 for holes.

<Explanation of the water-impervious test method at the original position of the blocking material in the borehole>
With respect to the water-imperviousness test system at the blocking member in-situ position of the boring hole configured as described above, the overall measurement flow will be described with reference to FIGS. 1 to 5 and FIG. Here, FIG. 6 is a view for explaining a water-imperviousness test method at a boring hole blocking material in-situ position, which is realized using the boring hole blocking material original position at the boring hole blocking material original position according to the present invention. It is a flowchart. Moreover, FIG. 7 shows a test pattern in the water-blocking test method at the blocking material in-situ position of the boring hole realized by using the water-blocking test system at the blocking material in-situ position of the boring hole according to the embodiment of the present invention. FIG. FIG. 7 (a) shows a pattern in which the micro flow rate metering pump is infused and stopped according to the test pattern, with the horizontal axis representing time and the vertical axis representing the amount of water injected into the pump. FIG. 7B shows the pressure measured by the pressure measuring sensor according to the test pattern, with the horizontal axis representing time and the vertical axis representing measured pressure. FIG. 7C is a graph for obtaining the hydraulic conductivity.

First, after the boring hole 2 is opened and necessary processing is performed, it is assumed that the placement of the blocking material in a certain section of the boring hole 2 is completed.
The test is now started. First, the logging cable 11 is wound around the drum of the winch 91 via the pulley 93 and the pulley 92, and the moat pipe 33 is lifted (S101). The measurement probe 3 is set at the tip of the moat 33 that has been lifted to a predetermined position (S102). Next, in the measurement probe 3, the logging cable 11 wound around the drum of the winch 91 is hung inside the boring hole 2 by the power of the winch 91 via the pulley 92 and the pulley 93. Then, the inside of the borehole 2 is lowered (S103).

 When the measurement probe 3 is placed on the closing member 4 inside the borehole 2, the high-pressure pump 52 is operated by a drive control command from the packer control device 51 of the packer drive control device 5, for example, high-pressure gas (High-pressure air) is supplied from the high-pressure pump 52 to the inflatable packer 30 of the measurement probe 3 through the high-pressure tube 13 for holes. As a result, the inflatable packer 30 of the measurement probe 3 expands and comes into close contact with the inner wall of the boring hole 2, and blocks the space above and below the inflatable packer 30 of the measurement probe 3 (S104). In this state, the bottom surface 31 a of the measurement base container 31 of the measurement probe 3 is in a state of being firmly pressed onto the blocking material 4.

  Next, the measurement data from the pressure / temperature measurement sensor 37 and the pressure measurement sensor 38 inside the measurement probe 3 is taken into the measurement / control device 7, and the background pressure / temperature is measured by the measurement / control device 7. Measure (S105), and the measurement / control device 7 determines that the background pressure / temperature is not stable (for example, taking the difference between the measurement value before a certain time and the current measurement value, and the difference is a predetermined reference If it is determined that the value has been exceeded (S106; NO), the measurement / control device 7 again performs the background pressure / temperature measurement process (S105). These steps 105 and 106 are executed in the measurement / control apparatus 7 until the background pressure / temperature is stabilized (period t0 to t1).

Since the background pressure / temperature is actually stabilized near the time t1 in FIG. 7B, the measurement / control device 7 uses the measurement values from the pressure / temperature measurement sensor 37 and the pressure measurement sensor 38 as a basis. If the background pressure or temperature is determined to be stable (S106; YES), the measurement / control device 7 operates the minute flow rate metering pump 391 of the water injection means 39 and operates the solenoid valve 392 as necessary. Water injection is started (time t1; S107). The water injection from the minute flow rate metering pump 391 is injected into the upper portion of the blocking material 4 from the water injection outlet 35 via the capillary tube 390.
The measurement / control device 7 monitors the measurement data from the pressure / temperature measurement sensor 37 / pressure measurement sensor 38 (S108), while the measurement data relating to the pressure from the pressure / temperature measurement sensor 37 is shown in FIG. 7 (b). When P1 is reached (time t2), the operation of the minute flow rate metering pump 391 of the water injection means 39 is stopped and water injection is stopped (S109).

  Then, the measurement / control device 7 collects measurement data detected by the pressure / temperature measurement sensor 37 / pressure measurement sensor 38 for a predetermined section (time t2 to time t3) after the end of the time t2 (S110). When sufficient fall-off data has been acquired (S111), a permeability coefficient calculation process is performed (S112). The details of the process for calculating the hydraulic conductivity will be described later.

  Next, after completion of the water permeability coefficient calculation process (S112), the measurement / control device 7 again turns on the micro flow rate metering pump 391 of the time water injection means 39 at time t3 in FIGS. 7 (a) and 7 (b). In addition to starting the operation, the electromagnetic valve 392 is operated as necessary (S113) to start water injection from the water injection outlet 35 to the upper portion of the blocking material 4 through the capillary tube 390. Then, the measurement / control device 7 detects the measurement data while taking in the detection measurement data from the pressure / temperature measurement sensor 37 and the pressure measurement sensor 38 (S114).

  The measurement / control device 7 continues to monitor the measurement data that changes from time to time supplied from the pressure / temperature measurement sensor 37 and the pressure measurement sensor 38 (S114-S115; NO). Here, the measurement / control device 7 uses the pressure P2 at which the pressure measurement data from the pressure / temperature measurement sensor 37 and the pressure measurement sensor 38 suddenly decreases from the pressure P2 to the pressure P3 as shown in FIG. 7B. Is detected (S115; YES), the measurement / control device 7 stores the pressure P2 as a break pressure and stops the operation of the minute flow rate metering pump 391 of the water injection means 39 (S116). Then, the measurement / control apparatus 7 calculates the strength of the closing material 4 based on the break pressure (S117). The process for calculating the strength of the blocking material 4 will be described later.

  The water-imperviousness test method at the blocking member in-situ position of the borehole can be provided by the above-described series of flows. The water-impervious test method at the blocking member in-situ position of the boring hole can be summarized as follows: the measuring probe 3 is lowered to the top of the blocking material 4 that closes the boring hole 2, and the boring hole 2 is moved to The step (S101 to S106) of shielding the inflatable packer 30 by inflating the inflatable packer 30 of the measuring probe 3 and the top and bottom of the inflating packer 30 of the measuring probe 3 are shielded in the step. After that, water is poured into the top of the blocking material 4 below the measurement probe 3 with a predetermined measurement pattern (FIG. 7A), and the pressure and temperature are measured by the pressure / temperature measurement sensor 37 and the pressure measurement according to the predetermined measurement pattern. A step of obtaining a hydraulic conductivity based on the measurement data from the sensor 38 (S107 to S112), and again after the completion of the step. Obtaining the break pressure and obtaining the strength of the blocking material (S113 to S117), and releasing the shielding after the step of obtaining the strength of the blocking material and taking out the measurement probe from the boring hole. It is provided.

Thereby, since a series of processing was complete | finished, the evaluation of the obstruction | occlusion material 4 of one boring hole 2 was complete | finished. Therefore, the process proceeds to the evaluation of the closing material 4 of the next boring hole 2.
According to such a water shielding test method at the original position of the blocking material in the borehole, the water permeability coefficient and strength at the original position of the blocking material 4 with the borehole 2 closed can be calculated, and a reliable evaluation is possible.

<Permeability analysis method for top of borehole plugging material>
A method for analyzing the hydraulic conductivity of the top of the borehole closing material according to the embodiment of the present invention will be described with reference to FIGS. In the method for analyzing the hydraulic conductivity of the top of the borehole closing material according to the embodiment of the present invention, the measurement probe 3 is lowered to the top of the closure material 4 that closes the borehole 2, and the borehole is opened by the inflatable packer 30 of the measurement probe 3. 2 for shielding the upper and lower sides of the inflatable packer 30 of the measurement probe 3 (S101 to S106 in FIG. 6), and a micro flow rate metering pump 391 of the water injection means 39 of the measurement probe 3 according to a command from the measurement / control device 7 And the step of stopping water injection (S107 3109 in FIG. 6) after injecting water at a constant flow rate or constant pressure for a certain time at a pressure that does not deform the plugging material 4 (pressure P1 in FIG. 7A), and water injection Steps for obtaining pressure measurement data (S110 and S111 in FIG. 6) in the pressure drop section after the stop (time t2 to time t3 in FIG. 7B), and pressure measurement obtained in the above step The constant data is analyzed based on the Horner Plot method (using FIG. 7 (c)) to obtain the hydraulic conductivity of the pressure drop section.

Here, the Horner Plot method is a method used to determine the hydraulic conductivity of water wells, oil wells, etc., and the elapsed time after water injection or pumping is stopped at a constant flow rate for a fixed time. In the pressure transition section, the horizontal axis is called Horner time [(time of water injection or pumping) + (time elapsed after water injection or pumping stopped)] / (time elapsed after water injection or water pumping stopped) If the pressure value observed at that time is taken on the vertical axis, the slope of the straight line part that appears in the middle of the semilogarithmic graph assumes that the stratum around the well is a uniform porous object Based on the principle proportional to the hydraulic conductivity of the well, the hydraulic conductivity of the well is obtained.
Here, the permeability coefficient is k, the flow rate is Q [m ³ / s], the effective layer thickness is h [m], the viscosity coefficient of water is μ, and the permeability coefficient is kh / μ [m ³ / Pa · s. ] If the slope obtained by the Horner Plot method is m,
kh / μ = Q / (log (e) 4πm) [Equation 1]
It becomes.

  Further, Formula 1 will be described. Formula 1 shows a theoretical analysis formula for a hydraulic test in a well. First, the permeability coefficient k of the formation around the well is the effective thickness h of the formation, the viscosity coefficient μ of water, the flow rate Q and the injection time t of water injected into the well, the time Δt after the injection stop, In relation to the pressure value P, the slope m of the straight line portion on the graph (see FIG. 7C) in which the horizontal axis represents the logarithm of Δt (t + Δt) and the vertical axis represents the pressure P, is obtained. In such a case, the hydraulic conductivity k can be obtained from the formula 1.

<Description of strength analysis method for top of borehole plugging material>
A method for analyzing the strength of the top of the borehole blocking material according to the embodiment of the present invention will be described with reference to FIGS.
In this strength analysis method for the top of the borehole closing material, the measurement probe 3 is lowered to the top of the closure material 4 that closes the borehole 2 and the borehole 2 is expanded by the inflatable packer 30 of the measurement probe 3. A step (S101 to S106) of shielding the upper and lower sides of the type packer 30, and after blocking the upper and lower sides of the inflatable type packer 30 of the measuring probe 3 in the step, the blocking material 4 below the measuring probe 3 Steps (S107 to S112) of injecting water with a predetermined measurement pattern (time t1 to t2 in FIG. 7 (a)) to obtain the pressure and temperature by the predetermined measurement pattern, and after completion of the above steps, Steps (S113 to S116) for obtaining a break pressure (pressure P2 in FIG. 7B) by re-injecting water with the water injection amount shown in FIG. A step of obtaining the strength of the plugging material 4 placed in the borehole 2 based on the relationship between the strength of the plugging material 4 and the break pressure (P2) acquired in the steps (S113 to S116) (S117). It is equipped with.
The actual strength of the blocking member 4 can be obtained by such a strength analysis method for the top of the blocking member.

  The above describes the contents customary for the water-blocking test etc. at the source of the blocking material of the boring hole, but the feature common to the measurement probe in this case is water injection for applying pressure to the top of the blocking material on the measurement probe. It is a point that a part container 32 (water injection means 39), a so-called minute flow rate metering pump 391, a solenoid valve 392 and a water storage container 393 are incorporated. By configuring this structure, in the conventional example, the pressure water is supplied to the bottom of the bore hole by the pressure water supply pipe penetrating the bore hole from the ground, and means such as the pressure water supply pipe is unnecessary. As a whole, it is possible to realize a water-impervious test method or the like at the original position of the closing material of the boring hole that is compact and inexpensive.

<Explanation of experimental equipment for borehole plugging material in water shielding chamber>
FIG. 8 is a block diagram showing an experimental apparatus for a water blocking chamber for a boring hole blocking material according to the present invention. In FIG. 8, the experimental apparatus for a borehole plugging material in a boring hole according to the present invention is a test apparatus for simulating the measurement with the measurement probe 3. The purpose is to verify the analysis technique used.

  As shown in FIG. 8, an experimental apparatus 40 for a boring hole blocking material according to the present invention includes a pressure vessel 41 that can accommodate a blocking material 4 such as a boring hole, and the pressure vessel 41 with the blocking material 4. A water introduction outlet 42 that can be inserted into an arbitrary location on the top of the plugging material 4 and that can be poured into the upper part of the plugging material 4 when being accommodated, and is provided a predetermined distance away from the water injection outlet 42. 4, a pressure introduction port 43 that can be inserted into an arbitrary position above the pressure vessel 4, pressure gauges 44 and 45 that allow the pressure at the top and bottom of the pressure vessel 41 to be visually observed, and the pressure and temperature of the water injection outlet 42 The temperature / pressure measurement sensor 46 capable of measuring the pressure at the measurement inlet 43, the water injection means 47 that enables water injection to the water injection outlet 42, and the measurement data from the temperature / pressure measurement sensor 46 are taken in and analyzed. Measurement Data analysis means (personal computer) is obtained by a 48.

A further description will be given of the experimental apparatus for a boring hole blocking material having such a configuration. A water injection outlet 42 and a measurement inlet 43 are inserted from the upper part of the closing member 4 enclosed in the pressure vessel 41. The water injection outlet 42 and the measurement inlet 43 can be freely changed in position, and have a structure in which the measurement probe 3 designed under various conditions can be verified.
The pressure vessel 41 has a valve-equipped drain 51 and a pressure gauge 44 for observing the lower pressure of the pressure vessel 41 at the lower part, and pressurizes from the upper part to discharge excess moisture contained in the closing material 4. be able to. A pressure gauge 45 for observing the upper surface pressure measurement of the pressure vessel 41 is attached to the upper surface. A three-way valve 53 capable of releasing the pressure to the atmosphere is connected to the water supply outlet 42 by a capillary tube via a valve 52 that can be opened and closed, and further connected to the minute flow rate metering pump 47 by a capillary tube.

On the other hand, a pressure / thermometer 46 is connected to the measurement introduction port 43 by a capillary tube via an openable / closable valve 54, so that the pressure / temperature can be continuously observed. The pressure / thermometer 46 can continuously record data as digital values in a computer 48.
This apparatus can perform a verification experiment for obtaining an appropriate performance value of the measurement probe 3 by verifying the design value in a room in a simulated manner at the design stage of the measurement apparatus. Further, by using the obtained data for verification of the analysis method, it is possible to determine the performance of whether the analysis method is appropriate.

<Others>
According to the present invention, the method of water-impervious test at the in situ position of the borehole plugging material, the method of analyzing the hydraulic conductivity at the top of the borehole plugging material, the strength analysis method of the top of the borehole plugging material, By using the water test system and the experimental equipment for blocking boreholes, the boreholes to be surveyed are selected when selecting disposal sites for high-level radioactive waste geological disposal and low-level radioactive waste geological disposal. It is possible to establish an evaluation method for setting the safety standard for the closing operation at the time. As a result, at the disposal site, the degree of freedom in selecting the survey boring point can be increased by eliminating the anxiety about the uncertainty of the blockage operation after the completion of the survey due to the implementation of the survey boring. It also has the effect of increasing the survey boring points and improving the accuracy of the survey, and reducing the uncertainty in selecting a disposal site.

  In addition to the radioactive waste geological disposal field, how to prevent the migration of pollution sources to groundwater is a major issue in the groundwater pollution field. In particular, it is a serious problem for the source of contamination to be connected to an uncontaminated groundwater formation through a well. By using this test method and equipment, it is possible to improve the reliability of groundwater contamination countermeasures implemented by the national and local governments by providing one inspection standard for these blockage operations.

It is a block diagram which shows the water-imperviousness test system in the obstruction | occlusion material original position of the boring hole which concerns on this invention embodiment. It is sectional drawing which shows the detailed structure of the measurement probe used with the water-imperviousness test system in the obstruction | occlusion material original position of the boring hole concerning this embodiment. It is a figure which shows the bottom face of the measurement base container of the measurement probe used with the water-imperviousness test system in the obstruction | occlusion material original position of the boring hole which concerns on this invention. It is a figure which shows the fundamental structure of the micro flow volume metering pump which comprises the water injection means provided in the inside of the measurement probe used with the water-imperviousness test system in the obstruction | occlusion material original position of the boring hole which concerns on this embodiment. It is a diagram which shows the water-imperviousness test system in the obstruction | occlusion material original position of the boring hole which concerns on this invention embodiment. It is a flowchart for demonstrating the water-imperviousness test method in the obstruction | occlusion material original position of the boring hole implement | achieved using the water-imperviousness test system in the obstruction | occlusion material original position of the boring hole which concerns on this invention. It is a figure which shows a test pattern in the impermeable test method in the obstruction | occlusion material original position of the boring hole implement | achieved using the impermeable material test system in the obstruction | occlusion material original position of the boring hole which concerns on this invention. It is a block diagram which shows the impermeable chamber experimental apparatus of the boring hole obstruction | occlusion material which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Water-blocking test system in the original position of the blocking material of a boring hole 2 Boring hole 3 Measuring probe 4 Blocking material 5 Packer drive control device 7 Measurement / control device 9 Measurement auxiliary mechanism 11 Logging cable 13 High-pressure tube 30 in hole Inflatable packer 31 Measurement base container 32 Water injection part container 33 Moat pipe 34 Cable head 35 Water injection outlet 36 Pressure measurement introduction port 37 Pressure / temperature measurement sensor 38 Pressure measurement sensor 39 Water injection means 40 Water blocking means experimental apparatus 41 for borehole blocking material Pressure vessel 42 Outlet for water injection 43 Inlet for measurement 44, 45 Pressure gauge 46 Temperature / pressure measurement sensor 47 Water injection means 48 Measurement data analysis means (personal computer)
391 Minute flow rate metering pump 392 Solenoid valve 393 Reservoir 3911 Cam 3912 Shaft 3913 Cylinder 3914 Piston

Claims (6)

A step of lowering the measurement probe on the top of the blocking material that closes the boring hole and shielding the boring hole above and below the measurement probe by the measurement probe;
After blocking the upper and lower sides of the measurement probe with the boring hole in the step, water is poured into the top of the closing material on the lower side of the measurement probe with a predetermined measurement pattern, and the water permeability coefficient is measured by measuring the pressure and temperature with the predetermined measurement pattern. The desired process;
After the completion of the step, water is injected again to obtain a break pressure to obtain the strength of the plugging material,
And a step of releasing the shielding after the step of obtaining the strength of the plugging material and removing the measuring probe from the borehole. An inflatable packer that expands by gas pressure or water pressure and adheres to the wall surface of the borehole;
A measurement base container provided at the lower end of the inflatable packer;
An outlet port for water injection provided in the measurement base container, capable of supplying water at a minute flow rate, and also serving as an inlet port for pressure measurement,
One or more pressure measurement inlets provided at a predetermined distance in the horizontal direction from the water injection outlet provided in the measurement base container;
A pressure / temperature measurement sensor attached to each pressure measurement inlet;
A water injection container provided in a portion to be an upper part of the inflatable packer when the inflatable packer is installed in the borehole;
A shape that can be inserted into the borehole, and is provided with water injection means that is contained in the water injection portion container, and has water injection means for injecting water in a fixed amount or constant pressure at a pressure that does not deform the blocking material at the water injection outlet. A measuring probe formed on
After placing the measurement base of the measurement probe on the top of the blocking material of the borehole, supply a predetermined gas pressure or water pressure to the inflatable packer at the time of measurement to firmly press the bottom of the measurement base container against the blocking material A packer control device for reducing the gas pressure or water pressure at the end of measurement,
After injecting water in the water injection means of the measuring probe at a constant flow rate or constant pressure for a certain period of time at a pressure that does not deform the plugging material, stop water injection and provide a water injection stop section. The measurement data from the pressure / temperature measurement sensor is taken in accordance with the measurement pattern, and the permeability coefficient at the original position of the plugging material or the plugging material source is determined from the acquired measurement data. A water-imperviousness test system at an original position of a blocking material in a borehole, comprising a measurement / control device for calculating the strength of the position.   The water injection means includes a micro flow metering pump, a solenoid valve provided between a discharge port and a capillary tube of the micro flow metering pump to prevent back flow when the pressure in the hole is higher than the pump pressure, and a suction of the micro flow metering pump. A water storage container that supplies water to the mouth, and is capable of feeding water to the water injection outlet provided in the measurement base container via a discharge port of a micro flow rate metering pump, a solenoid valve, and a capillary tube. The water-imperviousness test system in the blocking material original position of the boring hole according to claim 2.   4. The minute flow rate metering pump comprises a plunger type pump capable of feeding a constant amount of water by driving a piston in a cylinder with an electric cam and a shaft. Water-impervious test system at the original position of the blocking material in the borehole. A step of pushing the tip of the measurement probe into the top of the blocking material for closing the boring hole and shielding the boring hole from above and below the measuring probe by the measurement probe;
A step of stopping water injection after injecting water at a constant flow rate or constant pressure for a certain period of time at a pressure that does not deform the blocking material;
Obtaining pressure measurement data in the water injection stop section after water injection stop;
The method of analyzing the hydraulic conductivity of the top of the borehole obstructing material, comprising analyzing the pressure measurement data obtained in the above step to determine the hydraulic conductivity of the water injection stop section. A step of lowering the measurement probe on the top of the blocking material that closes the boring hole and shielding the boring hole above and below the measurement probe by the measurement probe;
After blocking the upper and lower sides of the measurement probe in the boring hole in the step, water is injected with a predetermined measurement pattern on the top of the closing material on the lower side of the measurement probe, and the pressure and temperature are acquired by the predetermined measurement pattern;
After completion of the step, water is injected again to obtain a break pressure;
A step of determining the strength of the plugging material placed in the borehole based on the relationship between the strength of the plugging material obtained in the physical property test of the plugging material subjected to the indoor water permeability test and the break pressure obtained in the step; ,
A method for analyzing the strength of the top of the hole for closing the borehole.

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